Land availability and policy commitments limit global climate mitigation from forestation

• 成果类型: Article
• 署名作者: Wang, Yijie; Zhu, Yakun; Cook-Patton, Susan C.; Sun, Wenjuan; Zhang, Wen; Ciais, Philippe; Li, Tingting; Smith, Pete; Yuan, Wenping; Zhu, Xudong; Canadell, Josep G.; Deng, Xiaopeng; Xu, Yifan; Xu, Hao; Yue, Chao; Qin, Zhangcai
• 署名单位: Sun Yat Sen University; Nature Conservancy; Smithsonian Institution; Smithsonian Environmental Research Center; Chinese Academy of Sciences; Institute of Botany, CAS; Chinese Academy of Sciences; Institute of Atmospheric Physics, CAS; Universite Paris Saclay; CEA; Centre National de la Recherche Scientifique (CNRS); University of Aberdeen; Peking University; Xiamen University; Commonwealth Scientific & Industrial Research Organisation (CSIRO); CSIRO Environment; Northwest A&F University - China; Chinese Academy of Sciences; Institute of Soil & Water Conservation (ISWC), CAS
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-10880
• DOI: 10.1126/science.adj6841
• 发表日期: 2025-08-28
• 页码: 931-934
• 关键词: carbon sequestration; terrestrial carbon; reforestation; accumulation; restoration; management; storage; soils

摘要

Forestation (afforestation and reforestation) could mitigate climate change by sequestering carbon within biomass and soils. However, global mitigation from forestation remains uncertain owing to varying estimates of carbon sequestration rates (notably in soil) and land availability. In this study, we developed global maps of soil carbon change that reveal carbon gains and losses with forestation, primarily in the topsoil. Constraining land availability to avoid unintended albedo-induced warming and safeguard water and biodiversity (389 million hectares available for forestation globally) would sequester 39.9 petagrams of carbon by 2050, substantially below previous estimates. This estimate drops to 12.5 petagrams of carbon with land further limited to existing policy commitments (120 million hectares). Achieving greater mitigation requires expanding dedicated forestation areas and strengthening commitments from nations with considerable but untapped potential.